And you obviously don't know what you are talking about if you think that code with a logic issue is easier to detect then code that does something completely different then it should.

Seriously, how long have you been programming and at what level? I programmed professionally for 8+ years (assembly, c, c++, perl, python). You can hide malicious code in logic issues aswell as using other techniques. For some examples (that I think you should be able to follow):

And this was in the crypto framework, which is quite advanced stuff and the mail mentioned key-leaking mechanisms. And no, it's not going to be any function call in the middle of the code called 'leak_keys()', I thought you were just trolling but it seems you are most likely very incompetent.